Vermifiltration Technology Research Articles

Sustainable pre-treatment of tempeh industry wastewater: Efficiency of vermifiltration in pollutant mitigation and compost production

This study investigated the efficacy of vermifiltration (VF) as a sustainable pre-treatment method for tempeh industry wastewater. Three lab-scale VF reactors using different earthworm feeds - cow dung (VF-1), tofu dregs (VF-2), and a combination of both (VF-3) - were used to evaluate their ability to reduce chemical oxygen demand (COD), biochemical oxygen demand (BOD₅), and total suspended solids (TSS), as well as pH. VF-3 exhibited superior performance, achieving reductions of 94.51 % in COD, 95.59 % in BOD₅, and 88.59 % in TSS with maintaining pH values between 6.73 and 6.87. The resulting vermicompost (VC) had high nutrient content, particularly in the VF-3 reactor, with values of 7.66 % C-organic, 1.19 % nitrogen (N), and a C/N ratio of 10.33, phosphate (P) 1.65 %, and potassium (K) of 0.37 %. Additionally, significant earthworm growth was noted in VF-3, suggesting enhanced organic matter breakdown. These results indicate that VF technology not only effectively reduces pollutants in wastewater but also produces nutrient-rich compost, offering a dual benefit for sustainable wastewater management in the tempeh industry.

The efficacy of integrated vermifiltration technology for treatment of food analysis laboratory wastewater

The macrophyte-assisted vermifiltration (MAVF) technology was applied for treatment of food analysis laboratory wastewater at Industrial Technology Institute (ITI), Sri Lanka for the first time. Three laboratory-scale sub-surface vertical flow units were established:1) without earthworms and plants (Control unit), 2) with earthworms (Eisenia fetida) (vermi-filtration unit (VF unit), 3) with both earthworms and macrophytes (Canna indica) (MAVF unit). Wastewater was fed batch-wise with a feeding rate of 10 mL/min and seven days hydraulic retention time (HRT) for eight consecutive batches. Physiochemical parameters, Chemical Oxygen Demand (COD), Total Phosphorus (TP), Total Nitrogen (TN), pH, of the influent and effluent of all three units were analyzed to investigate the treatment efficiencies. One-Way ANOVA was performed to evaluate the significant differences in treatment efficiencies. The mean COD removal efficiencies of the control unit, VF unit, and MAVF unit were 60.2 % ± 10.7, 71.6± 8.07 %, and 72.0 % ± 8.86, respectively. Average TN removal efficiencies of the control unit, VF unit, and MAVF unit were 8.05 % ± 5.75, 10.9±6.4 %, and 24.9 % ±12.84, respectively. Average TP removal efficiencies were 35.84 % ± 17.5, 35.84 % ± 17.5 %, and 40.0 % ±16.76, respectively. The COD removal displayed promising results, whereas the means for enhancing TP and TN removal should be further studied. The findings of this study sensitizes the testing laboratories to go green by adopting in-house cost effective laboratory wastewater treatment systems.

Nitrogen transformation dynamics in macrophyte-assisted high-rate vermifilter treating real domestic sewage

Due to economic and ecological sustainability, vermifiltration has become a popular alternative to conventional wastewater treatment methods. However, the science behind nitrogen removal in vermifiltration has yet to be adequately explored. Additionally, no study is available on assessing the performance of vermifilters/macrophyte-assisted vermifilters (VFs/MAVFs) at higher hydraulic loading rates (HLRs), which has been a significant loophole regarding the vermifiltration technology. The present study investigated the performance of a MAVF in terms of nitrogen transformation dynamics during the treatment of real domestic sewage subjected to higher HLRs. The designed MAVF ensured a decent removal of ammonium nitrogen (NH4+-N), total Kjeldahl nitrogen (TKN), organic nitrogen, and total nitrogen (TN). In contrast, there was a considerable gain in effluent nitrate nitrogen (NO3−-N) concentration than its influent concentration. The highest removal of NH4+-N (98.2 ± 0.7 %), TKN (99 ± 0.5 %), and organic nitrogen (100 %) corresponded to the experimental run with an influent COD of (200 ± 25) mg/L and HLR of (3 ± 0.1) m3/m2-d, whereas the experimental run with an influent COD of (200 ± 25) mg/L and HLR of (7 ± 0.2) m3/m2-d resulted in the maximum increase in effluent NO3−-N concentration (73 ± 10.6 times its influent concentration). The maximum TN removal of (87 ± 2.2) % was achieved for the experimental run with an influent COD of (700 ± 45) mg/L and HLR of (3 ± 0.1) m3/m2-d. The present research reinforces the suitability of MAVF technology as a cost-effective and ecologically benevolent bio-remediation alternative for domestic sewage.

A comparative study on the inhibitory effects imposed on earthworms by brewery and rice mill wastewater

Of late, vermifiltration (VF) technology has gained major attention from researchers as a sustainable wastewater treatment alternative in which the treatment of wastewater has been driven by earthworms (EWs). Apart from parametric effects, the composition, biodegradability/complexity, hydraulic and organic loading rates (HLR/OLR), and the concentration of organics present in wastewater exhibit inhibitory effects on EWs, declining the treatment efficiency of vermifilters (VFs), which have not been adequately explored. Hence, the present study dealt with the assessment of such inhibitory effects on the survival, growth, and reproduction of EWs using four kinds of wastewater. Results indicated that EWs sustained the flow of rice mill, real brewery, synthetic brewery, and the mixture of real brewery and domestic wastewater for 5–11, 11–21, 20–40, and 23–45 d, respectively, before reaching 50% mortality, at the HLR of 8–4 m3/m2-d. For each wastewater, the lowest HLR (4 m3/m2-d) yielded the highest growth of EWs. The mixture of real brewery and domestic wastewater provided the most favorable conditions for the reproduction of EWs, ensuring the highest number of cocoons (8–12 nos./EW) and juveniles (11–26 nos./EW) produced per EW, followed by synthetic brewery (cocoon: 3–9 nos./EW; juvenile: 5–18 nos./EW), real brewery (cocoon: 2–7 nos./EW; juvenile: 2–12 nos./EW), and rice mill wastewater (cocoon: 1–5 nos./EW; juvenile: 2–8 nos./EW), with the HLR varying inversely with the reproduction rate of EWs. Hence, the mixture of real brewery and domestic wastewater portrayed the least biological inhibition on EWs, whereas rice mill wastewater had the highest. Outcomes of the present study revealed that the VF technology is best suited for remediating the mixture of real brewery and domestic sewage, can substantially remediate synthetic brewery wastewater, and may treat real brewery and rice mill wastewater after an appropriate pretreatment. The premixing of real brewery wastewater with rapidly biodegradable and low-strength domestic sewage at a specific volumetric ratio improved the treatability of the former using the VF technology attributed to the enhanced biodegradability and reduced organic strength of the wastewater mix.

Vermifiltration: Strategies and techniques to enhance the organic and nutrient removal performance from wastewater

The vermifiltration (VF) technology has gained significant attention as a green alternative for remediating domestic and industrial wastewater over the last few decades. Of late, the implementation of various modifications to the orthodox VF technology, including tweaks in the design and operation of the vermifilters, has been portrayed in the available literature. However, owing to the scatteredness of the available information, the knowledge regarding the execution of the modified vermifilters is still inadequate. Hence, an effort has been made to comprehensively overview the innovative strategies and techniques adopted to improve the organic and nutrient removal potential of the VFs from wastewater. In addition, future perspectives have been recognized to design more efficient and sustainable VFs. This review explores more of such novel tactics to improve the performance of the VF technology regarding organic and nutrient removal from wastewater. PRACTITIONER POINTS: Innovative strategies and techniques implemented to VF technology were comprehensively overviewed. Design modification and advantages of each innovation were highlighted. The pollutant removal performance of every modification was emphasized. Modified vermifilters were better than the conventional vermifilters in terms of organic and nutrient removal from the wastewater.

Simultaneous Carbon and Nitrogen Removal from Domestic Wastewater using High Rate Vermifilter.

Being a cost-effective and environmentally benign technology, vermifiltration has significantly replaced the available conventional wastewater remediation methods in many cases over the last few decades. The present work emphasizes on the investigation of the nitrogen transformation dynamics, in addition to the organic carbon abatement in the designed high rate hybrid vermifilter. Moreover, the economical sustainability of the vermifiltration technology has also been enlightened by creating a bridge with the concept of circular bio-economy. The designed high rate macrophyte-assisted vermifilter (MAVF) ascertained significant high nitrogen and organic carbon removal efficiencies from the real domestic sewage, considering the chemical oxygen demand (COD) of the influent and hydraulic loading rate (HLR) as the input variables. The designed MAVF facilitated the maximum ammonium nitrogen (NH4 +-N), organic nitrogen, and total kjeldahl nitrogen removal efficiencies up to 98.2 ± 0.70%, 100%, and 99 ± 0.47%, respectively when COD of the influent and HLR were 200 ± 25mg/L and 3 ± 0.1 m3/m2-d, respectively. On the other hand, substantial enhancement in the nitrate nitrogen (NO3 --N) in the effluent (73 ± 10.55 times its influent concentration) was observed with influent COD of 200 ± 25mg/L and HLR of 7 ± 0.2 m3/m2-d. When the influent COD and HLR were maintained at 700 ± 45mg/L and 3 ± 0.1 m3/m2-d, respectively, the highest total nitrogen removal of 87 ± 2.25% was obtained. Alternatively, the influent COD of 200 ± 25mg/L and HLR of 3 ± 0.1 m3/m2-d yielded the highest COD removal efficiency of 77 ± 1.59%. Hence, the outcome of the present research work strengthens the suitability of the vermifiltration technology as an economically and ecologically sound natural wastewater bio-remediation technology for the treatment of domestic wastewater.

Effect of earthworms in reduction and fate of antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARGs) during clinical laboratory wastewater treatment by vermifiltration

In the recent decades, the role of wastewater treatment plants has been entrenched for the dissemination of antibiotic resistant bacteria into the environment. The present study explores the dynamics of earthworms-microorganisms interactions involved in the high treatment efficacy of vermifiltration technology along with reduction of antibiotic resistant bacteria (ARB). This study is the first of its kind to investigate the performance efficacy of vermifilter (VF) for clinical laboratory wastewater treatment. The results of the study showed that earthworms and VF associated microbial community had a significant effect on Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) reduction (78–85%), coliforms and pathogen removal (>99.9%) and caused a significant shift in the prevalence pattern of ARB. Molecular profiling of resistance causing genes such as ESBL (blaSHV, blaTEM and blaCTX-M), MRSA (mec-A) and Colistin (mcr-1) confirmed the probable mechanisms behind the resistance pattern. The microbial community diversity in the influent, earthworm's coelomic fluid and gut and filter media layers associated with the VF assists in the formation of biofilm, which helps in the removal of pathogens from the wastewater. This biofilm formation further results in a paradigm shift in the resistance profile of ARB and ARG, specifically most effective against drugs, targeting cell wall and protein synthesis inhibition such as Ampicillin, Ticarcillin, Gentamicin and Chloramphenicol. These findings further validate vermifiltration technology as a sustainable and natural treatment technology for clinical laboratory wastewater, specifically for the removal of pathogens and antibiotic resistance.

Design, performance evaluation and investigation of the dynamic mechanisms of earthworm-microorganisms interactions for wastewater treatment through vermifiltration technology

The study brings insight to earthworms-microorganism's symbiotic interactions for wastewater treatment for the most essential mechanisms (antimicrobial and enzymatic activity) during vermifiltration. The results showed that vermifilter (VF) resulted in effluent with biochemical oxygen demand (BOD) <5 mg/L, chemical oxygen demand (COD) <30 mg/L, coliforms <103 MPN/100 mL, signifying higher treatment efficacy. The study reported the microbial community diversity for influent, effluent, filter media, earthworm's body, casts and its coelomic fluid to understand the correlations & symbiosis to decipher the mechanisms. The results further showed that earthworm body were dominated by Gammaproteobacteria, and the percentages arrived to 60% of the microbial species, while VF showed presence of Firmicutes and Actinobacteria, which signifies that earthworms had a profound effect on controlling microbial biomass and improving microbial activity. The protein profiling of the bacteria associated with VF showed that earthworms feeding and earthworm–microorganisms interactions were responsible for enhanced treatment performance.

Potential of distillery effluents for safe water through vermifiltration

Vermifiltration of wastewater using waste eater earthworms is a newly conceived novel technology. The present study evaluated BOD, COD and TS showing significant variation in decrease by 95%, 90% and 80% respectively through vermifiltration of distillery effluents. The nutrient contents (TN, TP, TK, TCa and TMg) in the vermicasts had increase (1.82 % in TN, 0.24% in TP, 2.15% in TK, 2.07% in TCa and 2.86 % in TMg) in the range of fold than the control level. The morphology of the control and experimental vermicast samples were analyzed with SEM and the image showed significant variation. The FT-IR spectrum analysis showed reduction of aliphatic/aromatic (C=C and OH) compounds in the vermicompost. Thus, the present study significantly highlights the vermifiltration technology in treating distillery effluent.

Assessment on overall efficiency of urban greywater treatment by vermifiltration in hot climate: enhanced pollutants removal

ABSTRACT Vermifiltration technology using Eudrilus Eugeniae could be an alternative low-cost option for the treatment of urban greywater, which is highly polluted with high concentrations of surfactants, sodium and cooking oil. In this study, the effects of these pollutants on performance of a vermifiltration system was tested over a period of 6 to 8 weeks by enriching raw greywater with various concentrations of anionic surfactants (0, 15, 45 and 135 mg/L), sodium (0, 1, 2 and 4 g/L) and refined palm cooking oil (0, 250 and 500 mg/L). The vermifilter system was made of gravel, sand and sawdust layers from the bottom to the top, on which 200 earthworms were added. The greywater used in this study was previously used for dishwashing and laundry by an urban poor household. The greywater quality was compared with the effluent to evaluate the system performance. BOD5, COD, TSS and E. coli removal efficiencies ranged from 93% to 98%, 68% to 93%, 88% to 96% and 1.4-3 ULog, respectively, which are within the range of efficiencies reported in the literature. High proportion of surfactants (95–99%) and oil (84–89%) were removed but sodium was not removed. Instead, an increase in sodium concentrations was observed in the filter over the experimental period. Statistical analysis shows that BOD5, COD, TSS and E. coli removal efficiencies were independent of surfactants, cooking oil and sodium concentrations (p < .05). Thus, short term or accidental exposure of the vermifilter to high concentrations of these three pollutants did not have significant effect on the system performance.

Biological treatment of distillery wastewater by application of the vermifiltration technology

In this study distillery wastewater was treated using the vermifiltration technology in a bid to reduce downstream contamination by the effluent. 10 kg of Eisenia fetida earthworms were used as the vermifiltration media in a 0.5 m × 0.5 m x 0.3 m vermifiltration bed over a 40 h period cycle. The distillery effluent physicochemical parameters which included pH, total Kjeldahl nitrogen (TKN), biological oxygen demand (BOD), total dissolved solids (TDS), total suspended solids (TSS) and the chemical oxygen demand (COD) were measured every 5 days. The vermicompost which was produced as a result of the vermifiltration process's nitrogen, phosphorous and potassium composition was also determined. The distillery effluent pH changed from acidic to neutral whilst a decrease of 94.9% was observed for the TKN, 91.1% for the BOD, 91.9% for the TDS, 92.4% for the TSS and 89.4% for the COD upon treatment with vermifiltration. The vermicompost, a by-product of the vermifiltration process had a nitrogen, phosphorous and potassium composition of 1.87%, 0.87% and 0.66% respectively.

Performance of A Pilot-Scale Vermifilter for the Treatment of A Real Hospital Wastewater

In this study, the performance of a pilot-scale vermifilter (VF) for the treatment of hospital wastewater using the earthworm species Eisenia fetida was evaluated. The earthworms’ gut acts as a bioreactor and can ingest the wastewater solid and liquid organic wastes and expel these as vermicompost. A pilot-scale vermifilter was installed and operated for 133 days in one of hospitals in Hamadan city; the designed system was fed with the influent passed through coarse and fine grillage and the sedimentation tank of the hospital’s sanitary collection system. In order to study the efficiency of the system, the variations of pH value, chemical oxygen demand (COD), biochemical oxygen demand (BOD5), and total suspended solids (TSS) were measured. In addition, a conventional geofilter (GF) without Earthworm was used as the experimental control. The vermifiltration caused a significant decrease in the levels of COD (75%), BOD5 (93%), and TSS (89%) as well as neutralized pH in the wastewater. Also, these contents in the geofilter were observed to be 65%, 71%, and 71%, respectively. The vermifiltration technology can, therefore, be applied as an environmentally friendly method for hospital wastewater treatment.

Earthworms: nature’s chemical managers and detoxifying agents in the environment: an innovative study on treatment of toxic wastewaters from the petroleum industry by vermifiltration technology

Earthworms are justifying the beliefs of Great Russian scientist Dr. Anatoly Igonin who said they are—“disinfecting, detoxifying, neutralizing, protective and productive”. Studies indicate that some species of earthworms can “bio-accumulate, biodegrade or bio-transform” any toxic chemicals including “heavy metals”, “organochlorine pesticide”, “herbicides”, and the lipophilic organic micro-pollutants like “polycyclic aromatic hydrocarbons” (PAHs). Worm vermicasts, due to the presence of “hydrophilic” groups in the “lignin contents” and “humus”, also provide wonderful sites for “adsorption” of heavy metals and chemical pollutants in wastewater. Vermifiltration of wastewater using waste-eater earthworms is a newly conceived novel technology with several economic and environmental advantages. The earthworm’s body and the their “vermicast” work as a “biofilter” removing BOD5 by over 90 %, COD by 60–80 %, TDSS by 90–95 %, and toxic chemicals and pathogens from wastewater. This was a pioneering work done on an extremely “toxic wastewater” from the petroleum industry. It contained mixture of “aliphatic” and “aromatic” volatile petroleum hydrocarbons (C 10–C 36) and “organochlorines” originating from the cooling liquids, waste engine and gear oil, waste transmission and brake fluid, grease, spilled petrol, and diesel oil. The aliphatic fraction contained cycloalkanes as well as a complex mixture of saturated toxic hydrocarbons. The aromatic fraction mainly consisted of PAHs, which are more toxic and persistent than the aliphatic part. The chemicals of concern were the total petroleum hydrocarbons (TPH), dichloromethane (DCM), dichloroethane (DCE), and t-butyl methyl ether (tBME). The tBME compound has raised global concern recently due to its high mobility and persistence in the environment and possible carcinogenicity. About 1,000 earthworms (species Eisenia fetida) were released in the soil of vermifilter bed. They not only tolerated and survived in the toxic petroleum environment but also bio-filtered and bio-remediated the dark-brown petroleum wastewater with a pungent smell into pale-yellow and odorless water indicating disappearance of all toxic hydrocarbons. The hydrocarbons C 10–C 14 were reduced by 99.9 %, the C 15–C 28 by 99.8 %, and the C 29–C 36 by 99.7 % by earthworms.

Vermiculture Technology: Reviving the Dreams of Sir Charles Darwin for Scientific Use of Earthworms in Sustainable Development Programs

Vermiculture technology is emerging as an “environmentally sustainable”, “economically viable” and “socially acceptable” technology all over the world. 1) Vermi-composting Technology (to manage most organic wastes); 2) Vermi-filtration Technology (to treat municipal & several industrial wastewater); 3) Vermi- remediation Technology (to treat & clean up contaminated lands); 4) Vermi-agro-production Technology (to produce chemical-free organic foods by worms & vermicompost); 5) Vermi-industrial Production Technology (to produce valuable industrial raw materials from worms). The use of earthworms as “waste managers” for efficient “composting of food and farm wastes” and as “soil managers” for “fertility improvement” and enhanced “farm production” were known for ages but now it is being more scientifically and also commercially revived. The other uses of earthworms for the benefits of environment and society (wastewater treatment, land remediation & production of valuable medicines even to combat cancer and heart diseases; raw materials for rubber, lubricant, soap, detergent & cosmetic, industries and protein rich feed materials for fishery, dairy & poultry industries are some “new discoveries”. We have successfully experimented with the first four technologies for management of “municipal solid wastes”, treatment of “municipal & industrial wastewater”, remediation of “PAHs contaminated soils” and production of “wheat & corn crops” by use of vermicompost at Griffith University, Australia, with excellent results. Wastes are degraded by over 75% faster than conventional systems and compost produced are disinfected, detoxified, richer in nutrients & beneficial soil microbes; BOD loads & TSS of wastewater is reduced by over 95%; PAHs from contaminated soils are removed by over 80% in just 12 weeks; and crops growths are promoted by 30-40% higher as compared to chemical fertilizers. Earthworms are both “protective” & “productive” for environment and society.

Continuous village sewage treatment by vermifiltration and activated sludge process

Rural sewage treatment is now paid more and more attention in China. Vermifiltration technology could be one of the practical options under the review of previous studies. It showed good removal rates of contaminants on small to pilot scales for short-term tests. However, the impacts of season, temperature or other unknown factors are usually not taken into account. In this study, a larger vermifilter was designed to treat the sewage on village scale for long-term operation. Filter material composition was optimized by a half year experimentation. The treatment effects of vermifiltration were also compared with traditional activated sludge process for the same influent sewage. The results showed that the designed vermifiltration system could continuously treat the sewage produced by more than 100 inhabitants per day. COD, BOD5 and SS concentration in outflow were rather stable despite the fluctuation of hydraulic loading rate and organic input during one year test. It can also remove N and P to some extent. A suspending design of vermifilter bed cause adequate oxygen content in outflow of vermifilter. The comparative test showed that the treatment efficacy of vermifiltration was similar as activated sludge process. Generally, this vermifiltration system has practical application value for village sewage treatment.